Replaced
by Sadistic Writer Alice
Summary: Okuda Manami died by unknown circumstances, leaving behind a note for her beloved twin: Continue on her mission to assassinate her teacher, and keep her classmates unaware of her passing. But Masami is so different in personality and skills, will she be able to pull it off? Or will someone discover the truth?
1. Your Will

**Author's note: Um, ya, I've gotten this idea into my head after animeandmangafangirl posted a review to Quilla and I's story Twins Time! So... ya, I've rolled this idea around, contemplating on: what if Okuda's twin is her exact opposite and is like really close to Asano? What if her twin is evil? What if she also becomes an assassin along with her sister and outshines her, creating some rivalry and tension? How would Karma react to the whole thing? If he got caught inbetween the two?**

 **Eventually I keep coming back to one idea: Okuda Manami dies, and her sister replaces her. So this is the idea I went with for this fic. This story kicks off right after the episode when Okuda first tries to poison Korosensei and fails. So, there will be lots of chapters mostly following the anime, but obviously some changes in character relationships and stuff because OC! yayyyyy! :D**

 **Replaced**

 **~ Your Will ~**

"Okuda Masami, your sister left a note for you, we found it in her pockets." the leader of the self-defense force, Karasuma Tadaomi says gravely, placing a piece of yellow paper on the table in front of me.

I take the note, and read it over carefully, a knot forming in my throat as I look at her shaky handwriting.

 _Dear Masami, I'm sorry. I don't have much strength left so I can't explain everything. I know that I can't be saved. My classmates in E I wanted to help them. Karasuma will explain to you what it is that we were doing. Please don't tell my classmates that I'm gone. I don't want to trouble them with such things, because our mission is more important. You have to replace me, and support them. Do your best, I know if it's you everything will work out. I love you, goodbye._

"You're an idiot.." I whisper, tears pouring down my face. Idiot. Idiot.. Idiot! You're a fool, to think that you would keep something like this from your own classmates! "STUPID IDIOT!" I yell, crumpling the paper in my hands angrily throwing it onto the ground. I slam my fists on the table, lowering my head, trying to stop my tears. "It's not fair... it's not fair at all. You always make things like this difficult! I hate.. hate that about you."

I don't know how many seconds, or minutes pass by, but Karasuma clears his throat and asks in a calm, professional way: "Okuda will you join E as your sister requested?"

I want to say no. But there's that heavy feeling in my chest: guilt. I have to say yes, I know I do. But it feels so wrong. I'm not like her, I don't want to help this mission or whatever.

I've got to suck it up and do what you asked, Manami. I have to, whether I like it or not. "Yes." I answer, rubbing my teary eyes looking up at Karasuma. "Now tell me: what do I have to do?"

Rest in peace, sister. I'll do what you couldn't. Because it's your will.


	2. Play The Part Assigned

A/N: hah~ this is the most difficult character I've ever made :p

Wow, ok, um, thank you all for the wonderful feedback!

To answer the question as to how Manami died: ... well you will find out some 10 plus chapters from now :P ok, maybe five or six chapters from now because the people that do know what happened may or may not choose to talk about it..

Sorry I'm a sadistic writer - if you can't tell from my pen name xD

 **Replaced**

 **~ Play The Part Assigned ~**

"Hi Kayano-san!" I gave a small smile and waved at the mirror in front of me. "Kayano-chan! Kaede-chan! Kaede! Kayano! UGH! I don't know!" I fall back onto my bed, dropping the phony smile and staring up at the ceiling. "Kayano Kaede, Nagisa, Karma, Kanzaki, Muramatsu, Terasaka, Chiba, Hayami, Kataoka, Isogai, Sugino, Yada... do I really need to know everybody's names?"

I guess I should be grateful.. That guy, Karasuma, he gave me some pictures of my classmates, of the classroom and the teacher. I've spent the entire day going over every picture, every name, and I've been practicing how to greet them - how I should address everyone. I've had to ask myself every single step of the way: is this how she would do it? Would she just keep her head down, or would she hold her head up and smile? She's not the most courageous person ever, so I imagine it took her a long time just to make one friend. Right, maybe I should just let the others talk to me first. Then I'll work out what to do from there.

Hm.. It kind of makes me jealous. She became friends with Kayano Kaede... she never told me anything. She needs to talk more about herself instead of science all the time. You make things awkward Manami, you know that? And now I'm crying, because I'm thinking about you. How unfair.

Downstairs the front door opens and slams shut. There's a bit of silence before the sound of shattering glass echoes through the house, followed by sobs and more glass breaking.

Dad's home from work. I stand to my feet, brush the tears away and bring my desk chair and put it underneath the doorknob. I flick the light switch off and crawl underneath the covers on my bed, and put in some headphones and drown out everything before falling asleep.

* * *

 _"Wh-when I grow up I want to be a scientific researcher."_

 _"When I grow up I want to be a fireman!"_

 _"What do you want to be, Masami-chan?"_

 _"I want to be me!"_

 _"Haha, no sweetie, what do you want to do, as in a career?"_

* * *

"HEY! HEY! WAKE UP! WAKE UP! WAKE UUUU-!"

I act on reflex, tapping the screen of my phone successfully turning off my alarm. I lift my head up, looking around the bright room. There hanging on a coat hanger is my new Kunugigaoka uniform.. or well, my sister's uniform.

That's right, today's the day I get rid of my identity, and go to school as my sister. Joy.

* * *

It really wasn't all bad walking to school. I wasn't approached by anybody, mostly because I got going early so that I could have some time to meet the teacher and have the circumstances explained to them. I'm hoping that Karasuma handled that, because I personally don't want to be there when they freak or break down and cry.

Climbing up a mountain path, I had time to think over things and look over the class schedule. There wasn't much difference between this one and my old schedule at my old school. Except for the assassination training. That's something else.

Walking into the school building, I had little trouble figuring out which rooms were which as I had examined the pictures of the interior of this place thoroughly. I knocked on the teacher's lounge door before entering. There was Karasuma, who apparently was the gym teacher, and then there was the homeroom teacher: a giant yellow octopus who moved at at unbelievable speeds, the target the class was supposed to kill before next March. The one responsible for destroying the moon. What a fierce opponent.

"OKUDA-SAN!" in an instant the said opponent was in front of me, tears streaming down his face as he clutched my hands in his tentacles. "I AM SO SORRY!"

What the hell?!

"Wh-what do you have to be sorry about?" I asked, raising an eyebrow.

He drew back his tentacles and used a handkerchief to dab at his eyes. "I was not there in her last moments, if I had been, perhaps this might not have happened. I do hope you understand, she meant a lot to this class, to me her educator. If you ever need to talk, feel free to come to me."

It makes me sick to my stomach when I see people look at me with pity - my family did, my best friend did and now.. he isn't showing any sign of pity. I don't know how to explain it, but the way that he looks at me, it's like he is in as much pain as I am - he isn't thinking I must be so sad.. he knows. He feels the same way that I do.

"Yes sir, I will if I need to." I mumble, looking down at the floor. Ah, I let myself cry a few tears, now I have to clean my glasses.

 _Plop._

I lift my head up, and the teacher has put a tentacle on top of my head.

"Do not worry, I'll make sure that no one will find out about this until you yourself are ready to tell them."

"Thank you sensei."

"For now, I guess you will just have to play the part assigned, Okuda-san. And I, Korosensei, will play the part as your mentor."

"Right." I smile up at him.

I think that I'll be able to make it work, Korosensei doesn't seem so bad.

"That's the spirit! You really got the Okuda-san smile right, though may I suggest to you that you clasp your hands together in front of you? She tends to do that often you know, while you are the opposite, you put your hands behind your back. You talk a tad faster than your sister does, and might I give you some hair tips? You have a loose strand of hair, Okuda-san never had that problem because of the way she carefully and neatly braided her hair." he continues to go on about things that I need to improve and moves around me with a hairbrush, comb and other hair products.

I take that back.

He irritates me.


End file.
